Modelling the Evolution of Sea Spray Droplets on a Global Scale

Sea spray droplets are an important mechanism for the transport of moisture, heat, and organic material between the ocean and the atmosphere. Spume droplets are the largest of the size spectrum and as such have the potential to transport significant amounts of energy and gases despite their generally short residence time in the atmosphere. A model is developed based on the physical parameterizations from Andreas et al. (1995, 2005)and a range of spume generation functions, coupled with a biogeochemical exchange model for gases developed here to examine the equilibrium temperature and gas exchange of spume droplets under representative open ocean conditions. The modelling approach uses micro-physics to simulate the expected changes to the droplet as it equilibrates with the atmospheric temperature and relative humidity. The effect of temperature differentials and relative humidity variations is explored. A global approach is simulated by using average summer and winter values for SST, salinity, and air temperature throughout the various ocean basins.